Grease-overflow catcher for highspeed motors



Nov. 7, 1939. E. o. MUELLER 2.179.341

GREASE-OVERFLOW CATCHER FOR HIGH-SPEED MOTORS Filed Dec. 51, 1936 WITNESSES: INVENTOR BYr/cb Q/WueV/e/T W 62% ATTORN EY Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE GREASE-OVERFLOW GAT'CHER FOR HIGH- SPEED MOTORS sylvania Application December 31, 1936, Serial No. 118,581

6 Claims.

My invention relates to lubricating means for dynamo-electric machines, and it has particular relation to improved means for catching the grease overflow of high-speed, grease-lubricated motors.

A particular object of my invention is to improve the operation of suction-ventilated, greaselubricated railway motors, which, because of the necessity for obtaining a large horsepower output in a very restricted space, must operate at high speeds and with a high-suction ventilating means. In all grease-lubricated motors, particularly where the grease is fed to the bearing from the outer end, which is the usual arrangement, it is necessary to provide a, drain at the inner end of the bearing for carrying away the grease escaping at that end, so as to prevent the same from being deposited on the inner working-parts of the motor. This escaped grease cannot well be returned to the grease-input end of the bearing, but is simply lost, being usually discharged into the open air outside of the motor.

Grease-lubricated motors, such as have just been described, have been known and in operation for years, and the grease-draining means has imposed a design-limitation upon the motor, particularly with respect to the amount of suction which could be tolerated in the region surrounding the inner end of the bearing, without drawing the escaped grease through the motor because of the air which is sucked in through the grease-drain.

An object of my invention is to provide a closed or air-tight sump for the grease to drain into, so that, no matter how much suction is imposed upon the inner end of the bearing by the motor-ventilating means, the grease escaping out of the inner end of the bearing cannot be drawn from the sump into the motor. Such a sump may readily be provided, which is of large enough capacity to hold the escaping grease which accumulates for a reasonable length of time, and it may be provided with drain-means whereby it may be momentarily opened for the purpose of removing accumulated grease from the sump.

A further object of my invention is to provide the sump in the end-housing of the motor, where there is sufficient room for providing a sump of the required grease-holding capacity, because the bearing cap or housing, which is necessarily a separate part, because of manufacturing exigencies, would not provide room for a sufficiently large closed sump in connection with the excessgrcase drain which has heretofore been normally provided in said bearing cap. In other words, I

provide a bearing drain and sump which extend between two separate members, starting in the bearing cap, and continuing on into the endhousing of the motor, which is a novel construction.

The accompanying drawing shows the preferred form of embodiment of my invention as applied to a railway motor having a stator member I, a

rotor member 2, and a ventilating means in the form of a fan 3, at the right-hand end of the motor, which serves to draw in air from the lefthand end of the motor, as shown by the arrows, thus creating a zone of sub-atmospheric pressure at the left-hand end of the machine, which is usually the end at which the commutator 4 is located (in the case of a direct-current machine as illustrated).

At the left-hand end of the machine, where the sub-atmospheric pressure exists, there is located a grease-lubricated bearing having a bearing-cap 6 which is provided, at its outer or lefthand end, with a grease-input chamber 1 which may be refilled, from time to time, by any suitable means, such as a grease-gun 8, which is temporarily applied to the hearing, as will be readily understood. The inner end of the bearing is provided with a labyrinth 9 for impeding the inward escape of the grease, and on the inward side of the labyrinth 9, the bearing-cap 6 is provided with a grease-drain l0. On the inner side of the grease-drain [0, the bearing-cap 6 is provided with a second labyrinth H for impeding the inward escape of grease into the machine from the drain I0.

According to my invention, I cause the bearing cap 6 to be so formed that the portion thereof which includes the drain l0, instead of discharging this drain to the outer atmosphere, cooperates with a part of the end-housing l2 which surrounds the bearing-cap 6 and which closes the left-hand end of the stator member I of the machine. I design this end-housing H with a closed sump I3, the upper portion of which is in operative connection with the drain I0, said connection being substantially air tight when the parts are assembled, as illustrated. The bottom end of the sump I3 is normally closed by suitable means, such as an air-tight draining-plug [4 which normally closes the sump from the atmosphere, but which may be removed, at times, for momentarily opening the sump to permit the removal of the accumulated grease therefrom.

In operation, the excess grease which slowly escapes from the inner end of the bearing 5 during the normal operation of the motor, or which rapidly escapes therefrom during the filling operation when the grease-gun 8 is rapidly forcing fresh grease into the bearing, escapes through the drain ii! and is deposited in the closed sump [3, where it accumulates. The provision of the closed sump l3, Which makes a substantially air-tight connection with the open end of the drain i0, prevents air from being drawn into the machine through the drain [0, notwithstanding the high suction which is created by the ventilating means or fan 3 of the machine, thus protecting the inner mechanism of the motor from being rapidly coated with grease from the drain H].

I claim as my invention:

1. A dynamo-electric machine having a stator member, a rotor member, a ventilating means which is operative to create a zone of sub-atmospheric pressure at at least one end of the machine, a grease-lubricated bearing at that end having a bearing-cap which is provided with a drain for grease escaping from the bearing at the inner end thereof, said dynamo-electric machine being provided with an end-housing surrounding said bearing-cap, said end-housing being provided with a closed sump in air-tight operative connection with said drain, and means for normally closing an opening in said sump from the atmosphere, said last-mentioned means being operative, at times, to be opened momentarily for removing accumulated grease from the sump.

2. A dynamo-electric machine having a stator member, a rotor member, ventilating means which is operative to create a zone of sub-atmospheric pressure at at least one end of the machine, means for providing a grease-lubricated bearing at that end of the "iachine, and for providing a closed airht sump for drain: ing grease escaping from the inner of the bearing.

3. A dynamo-electric machine having a stator member, a rotor member, a ventilating means which is operative to create a zone of sub-atmospheric pressure at at least one end of the machine, means for providing a grease-lubricated bearing at that end of the machine, means for feeding grease to the bearing from the outer end thereof, and means for providing a closed airtight sump for draining grease escaping from the inner end of the bearing,

4. The invention as defined in claim 1, in combination with means for impeding the escape of grease inwardly along the rotor member from said drain.

5. The invention as defined in claim 2, in combination with means for impeding the escape of grease inwardly along the rotor member from said sump.

6. The invention as defined in claim 3, in combination with means for impeding the escape of grease inwardly along the rotor member from said sump.

ERICH O. MUELLER. 

